Velocity pressure coefficient

Fy = minimum yield stress, shell, psi P = internal pressure, psi P,. = external pressure, psi G = gust factor, wind Kz = velocity pressure coefficient 1 = importance factor, 1.0-1.25 for vessels V = basic wand speed, mph Ks = pier spring rate, 46 fl — friction coefficient y = pier deflection, in. 

I = importance factor assume 7 = 1.0 V - design wind velocity (mph) from Fig. 16.3 Ki = velocity pressure coefficient... 

The velocity pressure coefficient factor, K, is determined from Table 4.2 (Table 6.3 of ASCE 7-2005 [2]). 

The velocity pressure coefficient, K, may be determined from the following ... 

Flow coefficients and pressure coefficients can be used to determine various off-design characteristics. Reynolds number affects the flow calculations for skin friction and velocity distribution. 

If the pressure coefficient just calculated is within 5 % of the original value of 0.29, then proceed using the calculated pressure coefficient and the assumed value of mean blade velocity as the final value. Continue to the speed calculation. If the pressure coefficient is higher than 5 %, add an additional stage to the compressor and again calculate the pressure coefficient using Equation 6.16. 

If the pressure coefficient is now, or was in an earlier step, 5% uiutei the 0.29 value, calculate a new mean blade velocity using the rounded off number of stages and the original pressure coefficient, 0.29. Use the calculated blade velocity in the subsequent step for compressor speed Calculate the speed. 

An external node represents a boundary node, i.e., a fixed pressure value or a location on the building facade which is linked to a specific set of vvind pressure coefficients for this location (a set of values for different wind directions Q ). The pressure at such a location e is then given by wind velocity at reference level p, air density) ... 

Nevertheless, in many cases, mean wind velocities can be assumed. In ventilation-system reliability studies, e.g., where minimum ventilation rates are to be determined, a calm situation with little wind must be assumed anyhow, and the need for accurate wind pressure coefficient data is not so obvious. 

Figure 12-461, Part 3. Stage performance of a compressor is usually represented in a pressure coefficient, n, or M, and efficiency, t), versus Q/N (capacity vs. speed). A given impeller stage design will have a different characteristic depending on the relationship of its operating speed to the inlet sonic velocity of the gas. For higher ratios of speed to sonic velocity, N/A , the head or pressure coefficient curve will be steeper at flows higher than the design. (Used by permission Bui. 423, 1992. Dresser-Rand Company.)...

P[3 = P[ = fan input power D = fan size (impeller or wheel diameter) N = fan speed Nj = fan specific speed p = fan air density Q = fan flow rate Kp = compressibility coefficient L, = sound power level Pjt = fan total pressure Pjy = fan velocity pressure Pj-s = fan static pressure... 

Tj = air or gas temperature at outlet, °R P, = fan outlet velocity pressure, in. water abs or other absolute units n = polytropic coefficient Cj = fan static efficiency, fraction... 

Brochet et al (Ref 3) studied the effect of ambient pressure on the detonation velocity of NM. Their measurements, corrected to an ambient temp of 277°K, provide a pressure coefficient of D of 0.197M/s/kbar. Thus at an ambient pressure of 1 kbar the increase in D (ca 6300m/sec at 1 bar) is only 197m/sec... 

U A brake system consists of a hollow cylinder and a sleeve of negligible thickness (Fig. 2P-6). The relative angular velocity, pressure, and coefficient of dry friction between the cylinder and sleeve are a>, p, and p, respectively. Find (a) the steady interface temperature, (b) the radius R corresponding to the lowest interface temperature. 

M being molecular weight and p" a density factor representing the available volume. This equation was used in a calculation of the temperature and pressure coefficients of the velocity of sound. The fact that both coefficients as calculated were on the low side suggests that the available volume in the liquid was over-estimated in this model. 

Polytetrafluoroethylene is a slippery material with a smooth surface due to its low coefficient of friction. Numerous mechanical applications have been developed for PTFE with slight or without lubrication, particularly at low velocities and pressures above 35 kPa. Table 3.26 contains values for coefficient of friction as a function of velocity. D5mamic coefficient of friction of PTFE is larger than its static coefficient of friction and grows with increasing speed until the motion is destabilized. Static coefficient of friction remains unchanged in the temperature range of 27°C-327°C which is important in applications where a polytetrafluoroethylene part may experience heat buildup and temperature increase. 

The first term on the left is important enough to be given a name in fluid mechanics, the pressure coefficient it is also sometimes called 1/(Euler num-ber)l It appears in problems in which there are significant changes in velocity and pressure between different parts of the system. For example, Eq. 6.53 may... 

The noncavitating pressure distribution for the Venturi is shown in Fig. 3. The data are plotted in terms of a pressure coefficient Cp as a function of the axial distance from the minimum pressure point. Cp is conventionally defined as the difference between the local wall and free-stream static-pressure head ijix — ho) divided by the velocity head F /2g. Free-stream conditions are measured in the approach section about 1 in. upstream from the quarter roimd. The solid line (Fig. 3) represents a computed ideal flow solution. The dashed line represents experimental data obtained with nitrogen and water in the cavitation tunnel and from a scaled-up aerodynamic model studied in a large wind tunnel. The experimental results shown are all for a Reynolds number of about 600,000. The data for the various fluids are in good agreement, especially in the critical minimum-pressure region. The experimental pressure distribution shown here is assumed to apply at incipient cavitation, or more exactly, to the single-phase liquid condition just prior to the first visible cavitation. 

Gy=gust response factor for flexible vessels h = height of vessel, ft I = importance factor, see Table 3-1 Iz = the intensity of turbulence at height z Kz = velocity pressure exposure coefficient from Table 3-3a, dimensionless Kct = topographic factor, use 1.0 unless vessel is located near or on isolated hills. See ASCE for specific requirements M = overturning moment at base, ft-lb Ni,Nh,Nb,Na = calculation factors... 

The procedures used to convert the wind velocity into applied forces for structures are consistent with current LWR practice. (Ref. 3, 4) The wind velocity on which the applied forces depend is given in Section 3.3.1.1. The design pressures or design loads are obtained by multiplying the effective velocity-pressures by appropriate pressure coefficients. (Ref. 3)... 

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